Canonical formula calculator
Customer Acquisition Cost
What it actually costs you to acquire one new customer, marketing and sales combined.
Worked example
How the number is worked out
A gutter-cleaning company that ran ads and paid a part-time closer for the month.
Starting from
Working
Every new customer cost $150 to find. Whether that is cheap or ruinous depends entirely on what one is worth over time — the same $150 is a bargain against a $900 customer and a slow death against a $120 one.
What this tells you
CAC is what it costs you, in real dollars, to add one new customer to your business — counting both marketing spend and sales spend. It is one of the few numbers that separates businesses that grow profitably from businesses that grow themselves into the ground.
When to use it
Calculate CAC monthly or per campaign. Watch the trend. Compare it to your gross margin per customer — if CAC is climbing faster than what each customer is worth, growth is destroying value, not creating it.
What it doesn’t tell you
CAC alone is meaningless without context. A $200 CAC is great if customers stay for years and spend thousands; it is a death sentence if customers leave after one purchase. Always look at CAC alongside customer lifetime value and payback period.
Reckon it, don’t just calc it
A calculator gives you today’s number. Reckon takes your plan to make your own money and checks it against what’s real — your margin, your price, what it takes to hit the take-home you want. No AI, no guessing — the same input always gives the same answer.